Practical Antenna Systems

for the Radio Collector

Beyond Wire Antennas

Al Klase – NJARC

10 Aug 2018

Your Dream Radio

Your Antenna

Why?

• 900 CHML – Hamilton, ON

– Old radio programs after 10PM

• 740 – Toronto

– Oldies

– Old programs

• 650 WSM – Nashville

– Quintessential Country

• Short Wave is not completely dead!

Antennas Launch and

Intercept Radio Waves

• It’s a Transducer

• Converts Electro-Magnetic Energy to Current in

an Electrical Circuit.

• And Vice Versa

Engineering is not a

Four-Letter Word

• Make measurements.

• Make decisions.

• Repeat as necessary.

Designing and building usable antennas

is a lot easier than designing radios.

Testing

• Building a good antenna system is an experimental

proposition. Careful testing is essential.

• Arrange an A-B switch to compare your new antenna to

the old "reference" antenna.

• It's usually best to work in daylight when atmospheric

noise is lower and ground-wave signals are available.

(minimum fading)

• Chose a marginal AM station and work for improved

reception. (In my case WMTR, 5KW, 21 miles.)

• A communications receiver with an S-meter is helpful but

not essential.

A/B Switch

An Indoor Antenna

Loops

• Respond only to the magnetic field.

• Household interference is generally an electrical field.

• Tuned: part of the radio front end.

• Less pickup than outdoor wire.

• Needs a high-gain receiver, i.e. superheterodyne.

So, why don’t we see many loops

between 1930 and 1940?

• Short-Wave!!

– Outside wire antennas remained the standard.

– Sophisticated designs appear on the market.

RCA Spiderweb

Loops

• Respond only to the magnetic field.

• Hosehold interference is generally an electrical field.

• Usually tuned: – Part of the radio front end.

– External control on the antenna.

• Broad-band (untuned) Active Loops are possible.

Commercial Tuned Loops

$30 on Amazon

Homebrew Tuned Loops

UTT-WILLIAMS AEROLOOP

Homebrew Tuned Loops

Even a caveman can do it!

DIY Broadband

Transformers

Antenna System

Probe Antennas

• Use a small antenna, in an advantageous position, to

capture a small sample of the desired signal.

• Make up the difference with a wind-band amplifier before

the receiver.

• Loops: Sample the magnetic field.

• Whips: Sample the electrical field.

Commercial Active Whip

Universal Radio

NTi GA3005

Wideband Antenna

Order #1343

List Price: $495.00

Your Price: $399.95

$42 – Ebay – F/Ukraine

Roelof Bakker, PA0RDT

http://www.kiwisdr.com/docs/pa0rdt_whip.pdf

N3FRQ Active Antenna

Active Antenna

Bias Tee

Untuned Shielded Active Loop

Commercial Active Loops • DX Engineering - RF-PRO-1B - $500

• Wellbrook ALA 1530 – £264

• W6LVP active loop - $250

• Experimenter’s Kit - $160

Homebrew - PA3GZK

Homebrew - PA3GZK

https://pa0fri.home.xs4all.nl/Ant/Active%20a

ntenna/Active%20receiving%20%20loop%2

0antenna%20eng.htm

Bleeding-Edge Technology

• Active Ferrite Loop Antenna

• Modern portable radios use untuned ferrite-rod antennas.

Tecsun PL-880 Tecsun PL-660

N3FRQ Active Ferrite Loop

Let Your Radio Play!

A conductor exposed to electro-

magnetic waves will absorb energy,

causing an alternating current to flow in

the conductor.

A conductor carrying an alternating electric

current will radiate energy as electro-magnetic

waves.

Antennas Launch and

Intercept Radio Waves

The Hertzian Antenna or Dipole

The Marconi Antenna

Connection to the Receiver

• You know what to do in this case.

• “G” is generally connected to chassis ground.

Many Multi-Band Sets

• These radios were designed to directly support balanced antenna

feedlines.

• Add a jumper for an unbalanced feed.

Anything is Better than

Nothing

Considerations

• Problem:

– А half wavelengeth at 1500 кнz is over 300 feet.

– А quarter wavelength at 600 кнz is over 375 feet.

• The Saving Grace:

– Because background noise is high, and receivers are fairly sensitive, а receiving antenna does not need to be highly efficient.

– Signal to noise ratio is far more important than absolute signal level.

– А modest size skywire сап give excellent results.

The Interference Zone

The Doublet Antenna

• Two random wires balanced above ground.

• Noise picked up by the feedline is cancelled out.

• Performance drops off drastically below the half-wave resonate

frequency.

• Great for Short Wave.

• No very good for BCB.

Probe Antennas

• Sample the Electromagnetic field with a small, inefficient antenna,

and make up the difference with an amplifier.

• Loops: sample the electrical field of the available signal, and ignore

the electrical field.

• Rods: E-field probe.

Rods (E-field Probes)

• Much, much shorter than the wavelength.

Practical Antenna Systems for the Radio Collector - Beyond Wire Antennas

A lot of us have acquired some really nice radios from the 1930’s, and then hang three

Practical Antenna Systems for the Radio Collector - Beyond Wire

Antennas

A lot of us have acquired some really nice radios from the 1930’s, and

then hang three feet of wire down the back of the table for an antenna. In

this presentation we’ll take a look at antennas systems in general with an

eye to modern solutions such as active antennas, that better fit a 21st

Century life style. Both commercial and homebrew setups will be

considered.

Commercial Active Loops

• W6LVP active loop

– http://www.w6lvp.com/

• DX Engineering - RF-PRO-1B - $500

• https://www.dxengineering.com/parts/dxe-rf-pro-

1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-

engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-

PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_Bw

E

• https://www.dxengineering.com/parts/dxe-rf-pro-1b $500

• Wellbrook L264

http://www.w6lvp.com/https://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1b?seid=dxese1&cm_mmc=pla-google-_-shopping-_-dxese1-_-dx-engineering&gclid=CjwKCAjwsdfZBRAkEiwAh2z65gl-PEYr8yjOoYgGrChVHMwulBrthDxIKGwGrJCDr_QtRkkOxdfv5BoCXeoQAvD_BwEhttps://www.dxengineering.com/parts/dxe-rf-pro-1bhttps://www.dxengineering.com/parts/dxe-rf-pro-1bhttps://www.dxengineering.com/parts/dxe-rf-pro-1bhttps://www.dxengineering.com/parts/dxe-rf-pro-1bhttps://www.dxengineering.com/parts/dxe-rf-pro-1bhttps://www.dxengineering.com/parts/dxe-rf-pro-1bhttps://www.dxengineering.com/parts/dxe-rf-pro-1b